Boiler.



No. 707,5l9. Patented Aug. [9; I902.

A. W. OFELDT.

BOILER.

(Application filed Sept. 28 1901.)

(No Model.)

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ATENT OFFICE.

AUGUST W. OFELDT, OF NEWARK, NEW JERSEY, ASSIGNOR, BY DIRECT AND MESNE ASSIGNMENTS, TO SALAMANDRINE BOILER COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

BOILER.

SPECIFICATION forming part of Letters Patent No. 707,519, dated August 19, 1902.

Application filed September 28, 1901. Serial No. 76,975. (No model.)

To aZZ whom may concern:

Be it known that I, AUGUST W. OFELDT, a citizen of the United States, residing at Newark, in the county of Essex and State of New Jersey, have invented certain new and usef ul Improvements in Boilers, of which the following is a specification.

My invention relates to improvements in steam-boilers, and particularly to improvements in small water-tube boilers, such as are used in automobiles, launches, and the ike.

My invention consists in the novel arrangement of the generating-tubes, and particularly in an arrangement of said. tubes and of a flame-guard surrounding the combustionchamber and directing the products of combustion inward, whereby heat is confined within the boiler and undue loss of heat by radiation avoided, in the novel method of introducing the feedwater, and heating the same before it reaches the steam and water chamber, in the novel construction of the steam and water chamber and the attachment of the burner thereto, and generally in the novel combination, construction, and arrangement of the parts.

The objects of my invention are to increase the efiiciency of water-tubeboilers, and par ticularly those of the class mentioned, to prevent excessive radiation of heat therefrom, to dispose the generating-tubes in a more efficient manner and utilize the same effectively for reducing loss of heat by radiation, to introduce the feed-water in animproved manner, to so construct and arrange the parts of chamber above and forming substantially a 5o continuation of water-chamber 1, the whole forming a steam and water drum or chamber.

Numerals 3 designate generating-coils arranged about the drum 1 and communicating therewith near the top and bottom and prefor decreasing the number of such coils the capacity of the boiler may be varied through a considerable range, while retaining one uniformsize of steam and water chamber. This greatly facilitates the manufacture of the boiler in a number of different sizes, be-

sides making iteasy to increase the capacity of any particular boiler if it be found too small for its work.

The boiler shown in the drawings is adapted to employ liquid'or gaseous fuel, and the burner is placed beneath the generatingcoils 3, so that the flames and heated products of combustion may pass upward through and around the coils .3 and around the waterchamber 1 and steam-chamber 2. The burner 7 5 shown inthe drawings isparticularly adapted to use a volatile liquid fuel under pressure, such as naphtha. Itconsists of a distributing-chamber at, preferably placed directly beneath and secured to the waterchamber 1, and from this chamber perforated burner-tubes 5 radiate. A fuel-supply pipe 6 is arranged to supply the fuel and at the same time to draw into the distributing-chamber 1 the necessary amount of air through an air-injector tube 7. "The burner screws upon the lower end of the water-chamber 1, and its bottom plate is also the bottom plate of the boiler-casing, the whole making a very convenient and elfective as well as compact 0 method of uniting a burner with the boiler; butI do not limit myself to the particular construction of burner shown nor to the particular method of associating the same with a boiler shown and described. A spiral coil of pipe 8, preferably formed of pipe of larger size than the generating-coils 3, surrounds these coils 3 and the water-chamber 1 and into it.

forms, substantially, a wall to confine Within 1 the boiler the heat of combustion, and thereby to prevent excessive radiation of heat from the boiler. This coil is connected with the water-chamber 1, at the bottom thereof, by a nipple 9, and is also connected with the waterchamber, atthe top thereof, preferably by a pipe 10, projecting through the side of the steam-chamber 2 and bent downwardly, as shown. The coil 8 therefore forms a portion of the circulating system of the boiler. It also forms a means whereby the feed-water may be heated before entering the waterchamber 1, for nipple 9 is connected to coil 8 by means of a T 11, to the third side of which is connected the feed-pipe 12, as shown particularly in Fig. 2, the feed-water being introduced in such direction that it tends to flow directly into the coil 8 ratherthan into the nipple 9, so that said feed-water helps to maintain the circulation through the coil 8. Moreover, the feed-water becomes heated by mixture with the water from the chamber 1 flowingv upward through the coil 8 and by the heat of combustion, so that by the time it reaches the water-chamber 1 itis at ahigh temperature. A shield 13 serves to direct the flame to the inner side of the coil 8. Said coil is surrounded by the usual casing 1 1, preferably formed of sheet metal lagged with asbestos or other suitable material and supported by the bottom plate above mentioned; but this casing will not be heated so highly as in former water-tube boilers of this class, because the pipe-coil 8 will intercept practically all of the heated gases. It will be noted, also, that the coil 8 which so intercepts the heat which otherwise would reach the casing is the coolest of all of the generating-coils, because through it the feed-water is introduced and because the heated gases have little access to the outer side of said coil. This makes the coil more eifective for intercepting the heat which otherwise might be radiated.

To the end of the pipe 10 above'mentioned there may be connected a baffle-plate 15 (shown in dotted lines in Fig. 1) to prevent water which may be carried up with the steam from passing directly to the main steampipe; but such baflie-plate is not essential. The steam is taken from the steam-chamber 2 through a perforated dry pipe 16.

In constructing the smaller sizes of this boiler, such as are particularly adapted. for automobiles and small steam-launches, both the steam-chamber 2 and the water-chamber 1 may be formed from wrought-iron or steel pipe of the proper size. For this purpose the pipe forming the cylindrical wall of the steamchamber 2 may have Welded into it an upper head 17 and a lower head 18, the latter having a central screw-threaded aperture, into which the water-chamber may be screwed. In like manner the lower end of the waterchamber may be closed bya head 19, welded By constructing the boiler in this manner the expense of constructing it may be made quite small.

In the operation of this boiler the waterlevel will not ordinarily be carried as high as the upper orifices of the inner row of generating-coils 3, although it may be carried higher without injury. The water-level may be carried as low as desired. I have found in actual use of boilers of the type shown in the drawings that they are not appreciably injured nor are their joints caused to leak if the water in them be evaporated to dryness. When this happens, of course the engine supplied by the boiler stops, thereby showing that the water in the boileris exhausted; but after the tubes have been allowed to cool somewhat the boiler may be refilled and the generation of steam commenced without danger. The generating-coils 3 and S expand and contract freely with changes of temperature and without straining the joints at the points of connection with the water-chamber 1 and steam-chamber 2, and said coils may be heated to redness without so reducing their strength as to render them liable to burst. The steam-chamber 2 is surrounded by the products of combustion as they pass to the otftake, which therefore tend to dry and even to superheat the steam therein.

Having thus completely described my invention, what I claim, and desire to secure by Letters Patent, is

1. In a boiler, the combination with a steam and Water chamber, of generating-tubes connected therewith, a coiled generating-tube surrounding said steam and water chamber and first-mentioned generating-tubes, and connected with said chamber,said coiled outer tube having closely-wound coils forming substantially a wall adapted to confine within itself the products of combustion and heated gases by which said generating-tubes are heated, and a combustion-chamber beneath the generating-tubes provided with an encircling flame-guard structurally separate from and independent of the generating-tubes of the boiler, extending substantially to the inner side of said outer coiled tube inclosing the entire space within which combustion takes place, and serving to prevent the passage of the products of combustion and heated gases to the outside of said coiled tube.

2. In a boiler, the combination with a steam and water chamber, of generating-tubes connected therewith, a coiled generating-tube surrounding said steam and water chamber and first-mentioned generating-tubes, and connected with said chamber,said coiled outer tube having closely-wound coils forming substantially a wall adapted to confine within itself the products of combustion and heated gases by which said generating-tubes are heated, said coil having a feed connection through which feed-water may be introduced, and a combustion-chamber beneath the generatingtubes provided with an encircling flame-guard structurally separate from and independent of the generating-tubes of the boiler, extending substantially to the inner side of said outer coiled tube inclosing the entire space within which combustion takes place, and serving to prevent the passage of the products of combustion and heated gases to the outside of said coiled tube.

3. In a boiler, the combination with a steam and water chamber, of generating-tubes con nected therewith, a generating-coil surrounding said steam and water chamber and gencrating-tubes, and connected with said chamber, the upper portion of said coil projecting into said chamber and bent downwardly, and a baffle-plate upon the end of said coil.

H. M. MARBLE, A. H. Drums. 

